EUNIS habitat classification 2017 > M - Marine benthic habitats > MC1 - Circalittoral rock > MC12 - Atlantic circalittoral rock > MC125 - Communities on Atlantic circalittoral soft rock > MC1251 - Piddocks with a sparse associated fauna in Atlantic circalittoral very soft chalk or clay

Piddocks with a sparse associated fauna in Atlantic circalittoral very soft chalk or clay

Description (English)

This biotope occurs on circalittoral soft rock, such as soft chalk or clay, most often in moderately exposed tide-swept conditions. As soft chalk and firm clay are often too soft for sessile filter-feeding animals to attach and thrive in large numbers, an extremely impoverished epifauna results on upward-facing surfaces, although vertical faces may be somewhat richer. The rock is sufficiently soft to be bored by bivalves. Species vary with location, but Pholas dactylus is the most widespread borer and may be abundant. Other species present may include the sponges Dysidea fragilis and Suberites carnosus and the polychaete Bispira volutacornis. Foliose red algae may be present on the harder, more stable areas of rock. Mobile fauna often include the crabs Necora puber and Cancer pagurus.
Situation: Subtidal chalk reefs or clay outcrops, mostly known from south-east England.

Source: EUNIS habitat classification

Quick facts

EUNIS habitat type code MC1251
Relation to Resolution 4 habitat type (used for designation of Emerald sites)

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Invertebrates Bispira volutacornis
Invertebrates Cancer pagurus
Invertebrates Dysidea fragilis
Invertebrates Necora puber
Invertebrates Pholas dactylus
Invertebrates Suberites carnosus
Species scientific name English common name Species group
Bispira volutacornis Invertebrates
Cancer pagurus Invertebrates
Dysidea fragilis Invertebrates
Necora puber Invertebrates
Pholas dactylus Invertebrates
Suberites carnosus Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 2007 (revised descriptions 2012) A4.231 Piddocks with a sparse associated fauna in sublittoral very soft chalk or clay same
For relation to plant communities (syntaxa), see Vegetation types

History

Classification Code Habitat type name Relationship type Comment
EUNIS Habitat Classification 200410 A4.231 Piddocks with a sparse associated fauna in sublittoral very soft chalk or clay same
EUNIS Habitat Classification 200308 A3.2411 Hiatella arctica, bryozoans and ascidians on vertical infralittoral soft rock overlap
EUNIS Habitat Classification 200308 A3.681 Piddocks with a sparse associated fauna in circalittoral very soft chalk or clay narrower
EUNIS Habitat Classification 200202 A3.2411 Hiatella arctica, bryozoans and ascidians on vertical infralittoral soft rock narrower
EUNIS Habitat Classification 200202 A3.681 Piddocks with a sparse associated fauna in upward-facing circalittoral very soft chalk or clay narrower
EUNIS Habitat Classification 199910 A3.681 Piddocks with a sparse associated fauna in upward-facing circalittoral very soft chalk or clay narrower
EUNIS Habitat Classification 199910 A3.2411 Hiatella arctica, bryozoans and ascidians on vertical infralittoral soft rock narrower
MNCR BioMar 97.06 (Britain & Ireland) MCR.SfR.Pid Piddocks with a sparse associated fauna in upward-facing circalittoral very soft chalk or clay narrower
MNCR BioMar 97.06 (Britain & Ireland) IR.FaSwV.AlcByH.Hia Hiatella arctica, bryozoans and ascidians on vertical infralittoral soft rock narrower
European Environment Agency (EEA)
Kongens Nytorv 6
1050 Copenhagen K
Denmark
Phone: +45 3336 7100